Hainmueller, J., Lawrence, D., Gest, J., Hotard, M., Koslowski, R., & Laitin, D. (2018). A randomized controlled design reveals barriers to citizenship for low-income immigrants. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.1714254115 (Original work published 2018)